From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lukasz Majewski Subject: Re: [RFC v2 0/3] LAB: Support for Legacy Application Booster governor Date: Wed, 22 May 2013 12:27:00 +0200 Message-ID: <20130522122700.104ca5cd@amdc308.digital.local> References: <1367590072-10496-1-git-send-email-jonghwa3.lee@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-reply-to: Sender: cpufreq-owner@vger.kernel.org To: Viresh Kumar Cc: Jonghwa Lee , "Rafael J. Wysocky" , linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, Vicent Guittot , Daniel Lezcano , MyungJoo Ham , Lukasz Majewski List-Id: linux-pm@vger.kernel.org Hi Viresh, Thanks for reply. > On 3 May 2013 19:37, Jonghwa Lee wrote: > > From: Lukasz Majewski > > > 2. New LAB governor. > > It calculates number of idle CPUs (based on scheduler data). On > > this basis it chose proper first level polynomial function for > > approximation. Moreover it enables overclocking when single, heavy > > loaded CPU is running. > > Hi Lukasz, > > I am still not sure about this governor. Do you have some results > with which you can tell how is it better than ondemand/conservative? I will provide proper test results. As a test platform I've used Exynos4 CPU (4 cores) with TIZEN OS on it. > > With or without overclocking. i.e. Apply only overclocking support to > ondemand/conservative.. I think, that overclocking support is crucial here. As you pointed out - ondemand and conservative benefit from it. Therefore, I would urge for its mainline acceptance. (code for reference) http://thread.gmane.org/gmane.linux.kernel/1484746/match=cpufreq In this RFC (patch 1/3), I've decided to put the burden of overclocking support to platform code (cpufreq/exynos-cpufreq.c and cpufreq/exynos4x12-cpufreq.c). Those changes aren't intrusive for other boards/archs. Moreover overclocking is closely related to processor clocking/power dissipation capabilities, so SoC specific code is a good place for it. What DO need a broad acceptance is the overclocking API proposed at: include/linux/cpufreq.h This introduces interface to which others will be bind. It shouldn't be difficult to implement overclocking at other SoCs (as it was proposed for Exynos). Feedback is welcome, since I might have overlooked oddities present at other SoCs. > > If you are using Android, maybe check Interactive too (Though it > itsn't mainlined yet). I will also delve into "Interactive" governor. As a side note: The "core" cpufreq code modification (patch 3/3) counts only 22 lines, so this patch series definitely is not intrusive. > > @Rafael: What do you think about this patchset? > > -- > viresh -- Best regards, Lukasz Majewski Samsung R&D Poland (SRPOL) | Linux Platform Group